South Park‘s creators earned plenty of plaudits for putting all of the animated show’s episodes online in 2008, but now most of the adventures of Kenny, Cartman and the gang are heading behind the Hulu Plus paywall. Hulu’s owners will be hoping it proves an effective way of getting more customers to shell out the $8-a-month asking price for its premium platform.

To tempt you in, all of the 247 episodes will be available for free on the basic Hulu service until September 24, when the 18th season arrives. At that point, a selected number of rotating free episodes will be available on Hulu and the South Park Studios site, according to the official announcement. Hulu Plus subscribers will get next-day on-demand access to new episodes from the 18th season onwards.

“South Park has revolutionized TV and pushed boundaries with unparalleled topicality and daring humor,” said Hulu’s Head of Content Craig Erwich as the deal was unveiled. “South Park has been one of the top ten most popular shows of all time on the platform. We’re thrilled to offer the series to fans in its entirety.” Judging by the comments left underneath the blog post, South Park fans aren’t quite so thrilled about the move.

Hulu’s deal for exclusive streaming rights will run for at least the next three years, and the show is a valuable jewel to have in its crown: South Park first aired in 1997 and has gone on to become the third longest-running animated series of all time behind The Simpsons and Arthur. It’s picked up five Emmy awards and spawned a full-length movie in 1999.

According to David Carr in the New York Times the deal is worth $80 million, although this hasn’t been officially confirmed. With Netflix and Amazon Instant Video investing heavily in exclusive content, Hulu has to make sure it bags special deals of its own. The bad news for consumers is they require multiple subscriptions to stay on top of all their favorite shows.